Currently, this type of platform is built using two beams that are moved in translation on rollers to enter the suction tube. These beams pass through two openings arranged beneath a manhole of the suction tube and are fitted into a wall of the suction tube opposite the manhole. The operators then affix other beams to create a structure, for example a lattice structure, that is able to support a floor and they attach floor elements onto this structure. The platform thus formed notably enables operators to access the lower portion of the wheel of the hydraulic machine, without the operator having to be suspended inside the suction tube.
Assembling a platform of this type is costly and lengthy since it is necessary firstly to position the different beams within the suction tube and secondly to attach floor elements to the beams. Assembling this platform currently takes about four days and requires several operators assembling the beams manually. Disassembling the platform also takes about four days. During construction of the platform, the hydraulic machine is stopped. Thus, for a one-day inspection of a hydraulic machine, the hydraulic machine has to be stopped for nine days, which results in a significant loss of profit in terms of electricity production for a turbine, or the quantity of water pumped for a pump.